Has anyone closed off the silencer ports on the bottom of the Eaton M90.
I read aluminium filler or JB Weld works good. Anyone have any experience with this? How's it sound?

It has been done several times before using many methods including welding them shut. The problem is that anything you use is susceptible to very high heat and pressures so things like JB weld can break off, the motor ingests them and possibly causes internal engine damage.

-Joe

Aluminum filler?

Doesnt matter what it is it can break off, even welding them shut can fail.

Im not saying it will definitely happen, just that if I was going to do it I would research the strongest possible method for filling in gaps like that in aluminum because theres no sense in cheaping out on something that could cost you an entire engine.

Keep in mind too that welding on the SC case can have adverse effects as well, for more info search on Clubgp.com

-Joe

I agree with Joe. I thought about doing it on mine, and was going to have them welded shut by a professional aluminum welder, but decided not to. I've read that it doesn't really gain much performance, but does make the charger whine more. I didn't think it was worth the trouble or expense just to make it whine louder. Should be plenty loud already with the stock 3800 air box gone and being possitioned so close to the driver in a Fiero.

I can't even hear my SC over the engine. Too darn loud.

A GenV M90 is louder than a GenIII. My GenV has a fairly loud high pitched whistle at idle and a good solid whine under heavy accel. If you cant hear your SC than your exhaust is way too loud or your SC is worn to where its completely inefficient and just spinning instead of pushing air.

-Joe

How about tack welding .050 aluminum over them? I seriously want to do this. I want a head turner for a car maybe even a cop magnet. I want to hear from someone who has actually done it.

do you have the genV or genIII?

Weld them shut if you want more whine. Just make sure you get some actual penetration so the bead doesn't break off

The SC is a big chunk of metal. There is no way it will adversely affect the whole thing

I blocked the silencer ports off on my first setup. I did notice a little more while and a nice whistle at part throttle. I used JB weld and it held up for 10,000+ miles so far. I pulled the blower recently to see if any flaked off or cracked and none yet. I switched to a different blower and retired the blocked off one for personal research purposes.
Dave

------------------

www.hausofguru.com

[This message has been edited by bmwguru (edited 05-14-2011).]

Its a Gen2 I believe.(1998 GTP). I will have it off today and welded this week some time. But it wont be running for a couple of months. My goal is Fierorama in the fall. Thanks again.

a 98 is a gen III

Huh, learned something new today. Series II engine with a gen III supercharger.

Series II

Introduced in 1995, the Series II is quite a different engine. Although the stroke for the 3.8 L engine remained at 3.4 in (86 mm), and the bore remained at 3.8 in (97 mm), the engine architecture was vastly changed. The deck height is shorter than the Series I, reducing weight and total engine package size. This required that the piston connecting rods be shortened 1 in (25 mm), and the crankshaft was also redesigned. A new intake manifold improved breathing while a redesigned cylinder head featured larger valves and a higher compression ratio. The result was 205 hp (153 kW) and 230 lb·ft (312 N·m), better fuel economy, and 26 lb (12 kg) lighter overall weight (to 392 lb (178 kg)). The 3800 weighs only 22 lb (10.0 kg) more than the High Feature V6, despite being an all cast iron design. This is the only Series version of the Buick V6 to have longitudinal RWD versions built, and these versions were only used in the F-body Chevrolet Camaro and Pontiac Firebird, and in the Holden Commodore, Caprice, and Ute.

The new intake manifold greatly improved airflow. To meet emissions standards, an EGR tube was placed in the intake manifold to reduce combustion temperatures. This increases fuel mileage by a substantial margin.

The 3800 Series II was on the Ward's 10 Best Engines list for 1995 through 1997.

GM recalled 1.5 million vehicles with this engine on April 14, 2009 due to risk of fire from engine oil leaking under the valve cover gaskets onto hot exhaust manifolds. The fire could spread to the nearby plastic spark plug wire retainers on the valve cover and then to the rest of the engine compartment. GM fitted the affected vehicles with redesigned spark plug wire retainers.[3] These engines were noted for having problems with the plastic upper intake manifold cracking around the EGR passage. The lower intake gaskets and upper intake manifolds were revised, correcting all these issues.
L36 Naturally Aspirated
A variation of the L36 engine in a 1998 Holden VT Commodore
Another variation of the L36 engine in a 1995 Oldsmobile 88

This engine was used in the following vehicles:

* Buick Le Sabre
* Buick Park Avenue
* Buick Regal LS
* Buick Riviera
* Chevrolet Camaro
* Chevrolet Impala
* Chevrolet Lumina LTZ
* Chevrolet Monte Carlo (Z34, LT, SS)
* Holden Commodore (VS, VT, VX, VY)
* Holden Caprice (VS, WH, WK)
* Holden Ute (VU, VY)
* Oldsmobile Eighty-Eight
* Oldsmobile Intrigue
* Oldsmobile LSS
* Oldsmobile Ninety-Eight
* Oldsmobile Regency
* Pontiac Bonneville
* Pontiac Firebird
* Pontiac Grand Prix

L67 Supercharged
A 3800 Series II L67 Supercharged engine in a 1998 Buick Regal GS.

The L67 is the supercharged version of the Series II L36 and appeared in 1996, one year after the normally-aspirated version. It uses the Eaton Generation III M90 supercharger with a 3.8" pulley, a larger throttle body, fuel injectors, cylinder heads, and lower intake manifold than the L36 uses. Both engines share the same engine blocks, but compression is reduced from 9.4:1 in the L36 to 8.5:1 for the L67. Power is up to 240 hp (180 kW) and 280 lb·ft (380 N·m) of torque. Final drive ratios are reduced in most applications, for better fuel economy and more use of the engine's torque in the low range. The engine was built in Flint, Michigan. The engine was certified LEV in 2001.

This engine is or was used in the following cars:

* 1996–2005 Buick Park Avenue Ultra
* 1997.5–2004 Buick Regal GS / GSX (SLP)
* 1996–1999 Buick Riviera (optional 1996-97, std. 1998-99)
* 2004–2005 Chevrolet Impala SS
* 2004–2005 Chevrolet Monte Carlo SS Supercharged/Intimidator SS
* 1996–1999 Oldsmobile Eighty-Eight LSS (limited)
* 1996–2003 Pontiac Bonneville SSEi
* 1997–2003 Pontiac Grand Prix GTP / GTX (SLP)
* 1996–2004 Holden Commodore VS (series II), VT, VX, VY